Turbofan Variable Bypass Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas turbine power systems face inefficiencies and high specific fuel consumption, along with excessive exhaust gas emissions, necessitating improvements in thermal efficiency and thrust generation.
Innovation Solution
A turbofan engine with a variable area passageway that diverts a portion of the core exhaust stream into the bypass stream, utilizing an auxiliary duct and control valve to adjust the flow, creating an aerodynamic dam and controlling the pressure ratio and thrust, thereby optimizing engine efficiency and reducing fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional turbofan engine operates with fixed bypass ratio, then the engine structure is simple, but the thermal efficiency and fuel consumption cannot be optimized across different operating conditions
Solution Approach 1:
The patent applies dynamics by introducing a variable area passageway that can change its geometry between different operating states. The passageway transitions from a first configuration to a second configuration, enabling the engine to dynamically adjust the bypass ratio and core exhaust diversion according to operating conditions, thereby optimizing thermal efficiency without permanent structural complexity
Solution Approach 2:
The patent changes physical parameters by modifying the area of the passageway between core and bypass streams. This parameter change allows control over the division of exhaust flow, adjusting the effective bypass ratio and improving thermal efficiency across different flight regimes while maintaining a relatively simple overall engine structure
2Loss of energy
If core exhaust stream is diverted into bypass stream, then fuel consumption decreases, but the device complexity increases due to auxiliary duct and control mechanisms
Solution Approach 1:
The patent uses an auxiliary duct as an intermediary component to divert a portion of the core exhaust stream into the bypass stream. This intermediary structure enables energy optimization by recirculating hot exhaust gases to mix with bypass air, reducing the temperature differential and improving thermal efficiency while minimizing direct modifications to the main engine core
Solution Approach 2:
The variable area passageway serves multiple functions: it acts as a flow divider, a mixing chamber, and a temperature regulator simultaneously. By combining these functions into a single integrated structure, the patent reduces the need for separate auxiliary systems, thereby lowering device complexity while achieving fuel consumption reduction
3Use of energy by moving object
If variable area passageway is used to control flow division, then thermal efficiency improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent segments the passageway into distinct zones with different flow control characteristics. By dividing the complex variable area passage into manageable sections, each with specific geometric features, the design simplifies manufacturing while maintaining the ability to control flow division and optimize thermal efficiency
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances thermal efficiency, reduces specific fuel consumption, and decreases turbine inlet temperature, leading to improved fuel efficiency and reduced emissions.
Implementation Method 1
utilizing an auxiliary duct and control valve to adjust the flow, creating an aerodynamic dam and controlling the pressure ratio and thrust
Data Source
AI summary
A gas turbine engine is disclosed with a bypass flow path having a bypass nozzle positioned downstream of a fan; a core flow path having a compressor, a combustor, a turbine and an exhaust nozzle; an auxiliary duct fluidly connecting the core flow path and the bypass flow path downstream of the turbine; and a control valve operably connected to the auxiliary duct to control fluid flow from the core flow path into the bypass flow path.